docs: def _rename(self, node, name):
          '''
          Rename an internal node of the tree. If an annotation is already
          present, append the new annotation to the end of it. If a bootstrap
          value is present, add annotations are added after a ":" as per standard
          newick format.
  
          Parameters
          ----------
          node: dendropy.Node
              dendropy.Node object
          name    : string
              Annotation to rename the node with.
          '''
          if node.label:
              try:
                  float(node.label)
                  new_label = "%s:%s" % (node.label,
                                         name)
              except ValueError:
                  new_label = "%s; %s" % (node.label,
                                          name)
              node.label = new_label
          else:
              node.label = name